title: Bone morphogenetic protein-2 and retinoic acid induce neurotrophin-3 responsiveness in developing rat sympathetic neurons.
abstract: Expression of the receptor tyrosine kinase, Trk, determines the specificity of neurotrophin responsiveness of different neuronal populations during development. Recently it has become apparent that sympathetic neurons of rat superior cervical ganglia (SCG) acquire sensitivity to neurotrophin-3 (NT3) before they become dependent on the target-derived nerve growth factor (NGF) for their survival by sequential induction of TrkC and TrkA. The mechanism controlling the expression of TrkC as well as the source of NT3 at their initial developmental stage has, however, not been clarified. Here we show that the treatment of the perinatal rat SCG neurons which express high levels of trkA mRNA with bone morphogenetic protein-2 (BMP2) induced the expression of trkC mRNA. Induction of the functional TrkC receptor by BMP2 was confirmed by the enhancement of the survival response of these neurons to NT3. Treatment of SCG neurons with retinoic acid (RA) promoted the effect of BMP2 on the induction of trkC mRNA levels. BMP2 treatment, on the other hand, promoted the effect of RA on the suppressions of trkA mRNA levels and the NGF-dependent survival of the SCG neurons. Furthermore, BMP2/RA treatment induced the endogenous expression of NT3. These results indicate that specific environmental signals can regulate neurotrophin responsiveness of developing sympathetic neurons by differential alteration of the trk and neurotrophin expressions.
authors.affiliation: Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-Ku, Sapporo 060, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Kobayashi
authors.forename: M
authors.initials: M
authors.lastname: Fujii
authors.forename: K
authors.initials: K
authors.lastname: Kurihara
authors.forename: I
authors.initials: I
authors.lastname: Matsuoka
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000494:pharmacology*; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D017931:DNA Primers; D004622:Embryo, Mammalian; D005786:Gene Expression Regulation / Q000187:drug effects; D009414:Nerve Growth Factors / Q000494:pharmacology*; D009474:Neurons / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D020933:Neurotrophin 3; D016133:Polymerase Chain Reaction; D051381:Rats; D017208:Rats, Wistar; D020794:Receptor Protein-Tyrosine Kinases / Q000096:biosynthesis*; D020917:Receptor, trkA / Q000096:biosynthesis*; D020812:Receptor, trkC / Q000096:biosynthesis; D017475:Receptors, Nerve Growth Factor / Q000096:biosynthesis*; D017783:Superior Cervical Ganglion / Q000166:cytology / Q000378:metabolism*; D016212:Transforming Growth Factor beta; D014212:Tretinoin / Q000494:pharmacology*
chemical_list: C525720:Bmp2 protein, rat; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D017931:DNA Primers; D009414:Nerve Growth Factors; D020933:Neurotrophin 3; D017475:Receptors, Nerve Growth Factor; D016212:Transforming Growth Factor beta; D014212:Tretinoin; D020794:Receptor Protein-Tyrosine Kinases; D020917:Receptor, trkA; D020812:Receptor, trkC